...Sam Rosenblum; Elwin L. Mosier Abstract Crystals of essentially nonmetamict nioboeschynite-(Ce), a complex oxide with the general formula AB 2 O 6 , were identified in an alluvial concentrate from the Tofty tin belt in central Alaska. The mineral grains are mostly sand-size (0.2 to 1.5 mm), red...

... and phase transitions. To date, only limited information about the effects of elevated P on the zircon structure are available. The elastic constants of radiation-damaged (metamict) and nonmetamict zircon were determined in the 1970s by Özkan and co-workers by using ultrasonic measurements ( Özkan et al...

... of the elastic constants of nonmetamict zircon . Physics and Chemistry of Minerals , 2 , 215 – 224 . Özkan , H. , Cartz , L. , and Jamieson , J.C. ( 1974 ) Elastic constants of nonmetamict zirconium silicate . Journal of Applied Physics , 45 , 556 – 562 . Pilot , J. , Werner...

... that of the proper to unaltered nonmetamict mineral (Frondel, 1958). + Calculated sp, gr. of pyrochlore is 4.31 and microIite 6.31 ** Index of refraction depends upon the composition, and degree of alteration. The index increases with increasing content of Ta, Differential thermal analysis of the sample shows...

... of a nonmetamict zircon were 93 conducted by Özkan et al. (1974) at ambient conditions using UI. Subsequent UI measurements 94 on zircon were conducted at room-P high-T (up to 573 K) and room-T high-P (up to 1.2 GPa) 95 conditions (Ozkan, 1975; Özkan and Jamieson, 1978). Two recent studies by Ehlers et al. (2022...

... and Graham, 1996 ; King et al., 1997 ). In contrast, oxygen isotope ratios of nonmetamict igneous zircons generally preserve magmatic compositions because zircon is a refractory mineral, is resistant to recrystallization, and oxygen diffusion in zircon is slow ( Valley et al., 1994 ; Watson and Cherniak...

...Figure 2. Temperature-dependence of elastic stiffnesses of nonmetamict zircon. ( a ) Longitudinal elastic stiffnesses, ( b ) transverse interaction coefficients, and ( c ) shear stiffnesses. ...

... . Özkan , H.S. , and Jamieson , J.C. ( 1978 ) Pressure dependence of the elastic constants of nonmetamict zircon . Physics and Chemistry of Minerals , 2 , 215 – 224 . Özkan , H. , Cartz , L. , and Jamieson , J.C. ( 1974 ) Elastic constants of nonmetamict zirconium silicate...

... , Y. , Zhang , Z. ( 1994 ): Study of heat events of ore-forming Bayan Obo deposit . Acta Geoscientia Sinica , 30–31 , 95 – 101 . (in Chinese). Rosenblum , S. & Mosier , E.L. ( 1975 ): Nonmetamict nioboeschynite-(Ce) from Alaska . Am. Mineral ., 60 , 309 – 315...

... of porphyritic hornblende-biotite monzogranite (UWA 116417; 131°36′28″E 12°53′02″S) containing clear, euhedral zircon crystals, was selected for dating. Samples of the Mount Goyder Syenite contain mostly metamict zircon grains, so a specimen containing nonmetamict monazite was used for geochronology (UWA 116411...

..., it is nonmetamict and gives excellent diffraction profile. The powder X-ray diffraction data of matsubaraite are given in Table 2. The unit cell parameters were refined from the powder X-ray diffraction data with internal Si standard (NBS, #640b) using a computer program by Toraya (1993) : a = 13.848(7), b...

.... Szymański , J.T. , Owens , D.R. , Roberts , A.C. , Ansell , H.G. , and Chao , G.Y. , 1982 , A mineralogical study and crystal structure determination of nonmetamict ekanite ThCa 2 Si 8 O 20 : Canadian Mineralogist , v. 20 , p. 65 – 75 . Wang , S.X. , Begg , B.D. , Wang...

... ), such that contamination is not likely to affect the older than 1.66 Ga distributions seen in our study. AgePick ( Gehrels, 2009 ) was used to manually filter ages based on U/Th, U concentration, and concordance to find the youngest, nonmetamorphic (U/Th <10), nonmetamict (low U concentrations) grains to estimate...

... of nonmetamict allanites since the first refinement of the crystal structure of allanite by Ueda (1955) . However, because of the lack of accurate EMPA of REE ( Reed and Buckley, 1998 ; Nishida et al. , 1999 ), structural refinements of allanites have not been attempted under the fixed constraint...

... ): Database Sets 1–46, International Centre for Diffraction Data (ICDD), Newtown Square, Pennsylvania . Rosenblum , S. & Mosier , E.L. ( 1975 ): Nonmetamict nioboaeschynite-(Ce) from Alaska . Am. Mineral . 60 , 309 – 315 . Tomasic , N. , Gajovic , A. , Bermanec , V...

... uniform and highly clustered at 3.85‰ ± 0.33‰. Furthermore, zircon is very resistant to hydrothermal alteration because of the sluggish rate of oxygen diffusion of zircon ( Valley et al., 1994 ; Watson and Cherniak, 1997 ; Zheng and Fu, 1998 ). In addition, nonmetamict, low- magnetism zircons...

... ; Syme et al. , 1977 ). There have also been a number of studies using Raman spectroscopy to characterize the degree and nature of metamictization in zircon ( Zhang et al. , 2000 and references therein). Nevertheless, with regard to end-member nonmetamict zircon several aspects of the crystal...